/*!	 filecontainerzip.cpp
**	 FileContainerZip
**
**	......... ... 2013 Ivan Mahonin
**
**	This package is free software; you can redistribute it and/or
**	modify it under the terms of the GNU General Public License as
**	published by the Free Software Foundation; either version 2 of
**	the License, or (at your option) any later version.
**
**	This package is distributed in the hope that it will be useful,
**	but WITHOUT ANY WARRANTY; without even the implied warranty of
**	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
**	General Public License for more details.
**
*/

#ifdef USING_PCH
#	include "pch.h"
#else
#ifdef HAVE_CONFIG_H
#	include <config.h>
#endif

#include <cstring>
#include <cstdint>
#include <cstddef>

#include <libxml++/libxml++.h>

#include <ETL/stringf>

#include "zstreambuf.h"

#include "filecontainerzip.h"

#endif

using namespace std;
using namespace etl;
using namespace synfig;

namespace synfig
{
namespace FileContainerZip_InternalStructs
{

#pragma pack(push, 1)

struct DOSTimestamp {
    uint16_t dos_time;
    uint16_t dos_date;

    inline DOSTimestamp():
        dos_time(0), dos_date(0) { }

    inline explicit DOSTimestamp(uint16_t dos_time, uint16_t dos_date):
        dos_time(dos_time), dos_date(dos_date) { }

    inline explicit DOSTimestamp(time_t time)
    {
        tm *t = localtime(&time);
        dos_time = ((t->tm_sec  & 0x3f) >>  1)
                   | ((t->tm_min  & 0x3f) <<  5)
                   | ((t->tm_hour & 0x1f) << 11);
        dos_date = ((t->tm_mday & 0x1f) <<  0)
                   | ((t->tm_mon  & 0x0f) <<  5)
                   | ((t->tm_year & 0x7f) <<  9);
    }

    inline time_t get_time()
    {
        tm t;
        memset(&t, 0, sizeof(t));
        t.tm_sec  = (dos_time <<  1) & 0x3f;
        t.tm_min  = (dos_time >>  5) & 0x3f;
        t.tm_hour = (dos_time >> 11) & 0x1f;
        t.tm_mday = (dos_time >>  0) & 0x1f;
        t.tm_mon  = (dos_time >>  5) & 0x0f;
        t.tm_year = (dos_time >>  9) & 0x7f;
        return mktime(&t);
    }
};

struct LocalFileHeader {
    enum { valid_signature__ = 0x04034b50 };

    uint32_t signature;			// < Local file header signature = 0x04034b50 (read as a little-endian number)
    uint16_t version;			// < Version needed to extract (minimum)
    uint16_t flags;				// < General purpose bit flag
    uint16_t compression;		// < Compression method
    uint16_t modification_time;	// < File last modification time
    uint16_t modification_date; // < File last modification date
    uint32_t crc32;				// < CRC-32
    uint32_t compressed_size;	// < Compressed size
    uint32_t uncompressed_size;	// < Uncompressed size
    uint16_t filename_length;	// < File name length (n)
    uint16_t extrafield_length; // < Extra field length (m)
    // next:
    //   filename - n bytes
    //   extrafield - m bytes
    //   file data
    //   optional LocalFileDataDescriptor (if bit 3 (0x08) set in flags)

    inline LocalFileHeader()
    {
        memset(this, 0, sizeof(*this));
        signature = valid_signature__;
    }
};

struct LocalFileHeaderOverwrite {
    uint32_t crc32;				// < CRC-32
    uint32_t compressed_size;	// < Compressed size
    uint32_t uncompressed_size;	// < Uncompressed size

    inline LocalFileHeaderOverwrite()
    {
        memset(this, 0, sizeof(*this));
    }

    inline static size_t offset_from_header()
    {
        const static LocalFileHeader dummy;
        return (size_t)((const char *)&dummy.crc32 - (const char *)&dummy);
    }
};

struct CentralDirectoryFileHeader {
    enum { valid_signature__ = 0x02014b50 };

    uint32_t signature;			// < Central directory file header signature = 0x02014b50
    uint16_t version;			// < Version made by
    uint16_t min_version;		// < Version needed to extract (minimum)
    uint16_t flags;				// < General purpose bit flag
    uint16_t compression;		// < Compression method
    uint16_t modification_time;	// < File last modification time
    uint16_t modification_date; // < File last modification date
    uint32_t crc32;				// < CRC-32
    uint32_t compressed_size;	// < Compressed size
    uint32_t uncompressed_size;	// < Uncompressed size
    uint16_t filename_length;	// < File name length (n)
    uint16_t extrafield_length;	// < Extra field length (m)
    uint16_t filecomment_length;// < File comment length (k)
    uint16_t disk_number;		// < Disk number where file starts
    uint16_t internal_attrs;	// < Internal file attributes
    uint32_t external_attrs;	// < External file attributes
    uint32_t offset;			// < Relative offset of local file header.
    // < This is the number of bytes between the
    // < start of the first disk on which the
    // < file occurs, and the start of the local
    // < file header. This allows software reading
    // < the central directory to locate the
    // < position of the file inside the .ZIP file.
    // next:
    //   filename - n bytes
    //   extrafield - m bytes
    //   filecomment - k bytes
    //   next CentralDirectorySignature

    inline CentralDirectoryFileHeader()
    {
        memset(this, 0, sizeof(*this));
        signature = valid_signature__;
    }
};

struct EndOfCentralDirectory {
    enum { valid_signature__ = 0x06054b50 };

    uint32_t signature;			// < End of central directory signature = 0x06054b50
    uint16_t current_disk;		// < Number of this disk
    uint16_t first_disk;		// < Disk where central directory starts
    uint16_t current_records;	// < Number of central directory records on this disk
    uint16_t total_records;		// < Total number of central directory records
    uint32_t size;				// < Size of central directory (bytes)
    uint32_t offset;			// < Offset of start of central directory, relative to start of archive
    uint16_t comment_length;	// < Comment length (n)
    // next:
    //   comment - n bytes
    //   end of file

    inline EndOfCentralDirectory()
    {
        memset(this, 0, sizeof(*this));
        signature = valid_signature__;
    }
};

#pragma pack(pop)
}
}

using namespace synfig::FileContainerZip_InternalStructs;

void FileContainerZip::FileInfo::split_name()
{
    size_t pos = name.rfind('/');

    if (pos == String::npos || pos == 0) {
        name_part_directory.clear();
        name_part_localname = name;
    } else {
        name_part_directory = name.substr(0, pos);
        name_part_localname = name.substr(pos + 1);
    }
}

FileContainerZip::FileContainerZip():
    storage_file_(NULL),
    prev_storage_size_(0),
    file_reading_whole_container_(false),
    file_reading_(false),
    file_writing_(false),
    file_processed_size_(0),
    changed_(false)
{ }

FileContainerZip::~FileContainerZip()
{
    close();
}

unsigned int FileContainerZip::crc32(unsigned int previous_crc, const void *buffer, size_t size)
{
    static const unsigned int table[] = {
        0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA, 0x076DC419, 0x706AF48F, 0xE963A535, 0x9E6495A3,
        0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988, 0x09B64C2B, 0x7EB17CBD, 0xE7B82D07, 0x90BF1D91,
        0x1DB71064, 0x6AB020F2, 0xF3B97148, 0x84BE41DE, 0x1ADAD47D, 0x6DDDE4EB, 0xF4D4B551, 0x83D385C7,
        0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC, 0x14015C4F, 0x63066CD9, 0xFA0F3D63, 0x8D080DF5,
        0x3B6E20C8, 0x4C69105E, 0xD56041E4, 0xA2677172, 0x3C03E4D1, 0x4B04D447, 0xD20D85FD, 0xA50AB56B,
        0x35B5A8FA, 0x42B2986C, 0xDBBBC9D6, 0xACBCF940, 0x32D86CE3, 0x45DF5C75, 0xDCD60DCF, 0xABD13D59,
        0x26D930AC, 0x51DE003A, 0xC8D75180, 0xBFD06116, 0x21B4F4B5, 0x56B3C423, 0xCFBA9599, 0xB8BDA50F,
        0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924, 0x2F6F7C87, 0x58684C11, 0xC1611DAB, 0xB6662D3D,
        0x76DC4190, 0x01DB7106, 0x98D220BC, 0xEFD5102A, 0x71B18589, 0x06B6B51F, 0x9FBFE4A5, 0xE8B8D433,
        0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818, 0x7F6A0DBB, 0x086D3D2D, 0x91646C97, 0xE6635C01,
        0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E, 0x6C0695ED, 0x1B01A57B, 0x8208F4C1, 0xF50FC457,
        0x65B0D9C6, 0x12B7E950, 0x8BBEB8EA, 0xFCB9887C, 0x62DD1DDF, 0x15DA2D49, 0x8CD37CF3, 0xFBD44C65,
        0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2, 0x4ADFA541, 0x3DD895D7, 0xA4D1C46D, 0xD3D6F4FB,
        0x4369E96A, 0x346ED9FC, 0xAD678846, 0xDA60B8D0, 0x44042D73, 0x33031DE5, 0xAA0A4C5F, 0xDD0D7CC9,
        0x5005713C, 0x270241AA, 0xBE0B1010, 0xC90C2086, 0x5768B525, 0x206F85B3, 0xB966D409, 0xCE61E49F,
        0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4, 0x59B33D17, 0x2EB40D81, 0xB7BD5C3B, 0xC0BA6CAD,
        0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A, 0xEAD54739, 0x9DD277AF, 0x04DB2615, 0x73DC1683,
        0xE3630B12, 0x94643B84, 0x0D6D6A3E, 0x7A6A5AA8, 0xE40ECF0B, 0x9309FF9D, 0x0A00AE27, 0x7D079EB1,
        0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE, 0xF762575D, 0x806567CB, 0x196C3671, 0x6E6B06E7,
        0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC, 0xF9B9DF6F, 0x8EBEEFF9, 0x17B7BE43, 0x60B08ED5,
        0xD6D6A3E8, 0xA1D1937E, 0x38D8C2C4, 0x4FDFF252, 0xD1BB67F1, 0xA6BC5767, 0x3FB506DD, 0x48B2364B,
        0xD80D2BDA, 0xAF0A1B4C, 0x36034AF6, 0x41047A60, 0xDF60EFC3, 0xA867DF55, 0x316E8EEF, 0x4669BE79,
        0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236, 0xCC0C7795, 0xBB0B4703, 0x220216B9, 0x5505262F,
        0xC5BA3BBE, 0xB2BD0B28, 0x2BB45A92, 0x5CB36A04, 0xC2D7FFA7, 0xB5D0CF31, 0x2CD99E8B, 0x5BDEAE1D,
        0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A, 0x9C0906A9, 0xEB0E363F, 0x72076785, 0x05005713,
        0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38, 0x92D28E9B, 0xE5D5BE0D, 0x7CDCEFB7, 0x0BDBDF21,
        0x86D3D2D4, 0xF1D4E242, 0x68DDB3F8, 0x1FDA836E, 0x81BE16CD, 0xF6B9265B, 0x6FB077E1, 0x18B74777,
        0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C, 0x8F659EFF, 0xF862AE69, 0x616BFFD3, 0x166CCF45,
        0xA00AE278, 0xD70DD2EE, 0x4E048354, 0x3903B3C2, 0xA7672661, 0xD06016F7, 0x4969474D, 0x3E6E77DB,
        0xAED16A4A, 0xD9D65ADC, 0x40DF0B66, 0x37D83BF0, 0xA9BCAE53, 0xDEBB9EC5, 0x47B2CF7F, 0x30B5FFE9,
        0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6, 0xBAD03605, 0xCDD70693, 0x54DE5729, 0x23D967BF,
        0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94, 0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B, 0x2D02EF8D
    };

    unsigned int crc = previous_crc ^ 0xFFFFFFFFUL;
    unsigned char *char_buf = (unsigned char *)buffer;
    size_t remain = size;

    while (remain--) {
        crc = table[(crc ^ *char_buf++) & 0xFF] ^ (crc >> 8);
    }

    return crc ^ 0xFFFFFFFFUL;
}

String FileContainerZip::encode_history(const FileContainerZip::HistoryRecord &history_record)
{
    xmlpp::Document document;
    document.
    create_root_node("history")->
    add_child("prev_storage_size")->
    set_child_text(strprintf("%lld", history_record.prev_storage_size));
    return document.write_to_string_formatted();
}

FileContainerZip::HistoryRecord FileContainerZip::decode_history(const String &comment)
{
    HistoryRecord history_record;
    xmlpp::DomParser parser;
    parser.parse_memory(comment);

    if (parser) {
        xmlpp::Element *root = parser.get_document()->get_root_node();

        if (root->get_name() == "history") {
            xmlpp::Element::NodeList list = root->get_children();

            for (xmlpp::Element::NodeList::iterator i = list.begin(); i != list.end(); i++) {
                if ((*i)->get_name() == "prev_storage_size") {
                    String s;
                    xmlpp::Element::NodeList list = (*i)->get_children();

                    for (xmlpp::Element::NodeList::iterator j = list.begin(); j != list.end(); j++)
                        if (dynamic_cast<xmlpp::TextNode*>(*j)) {
                            s += dynamic_cast<xmlpp::TextNode*>(*j)->get_content();
                        }

                    history_record.prev_storage_size = strtoll(s.c_str(), NULL, 10);

                    if (history_record.prev_storage_size < 0) {
                        history_record.prev_storage_size = 0;
                    }
                }
            }
        }
    }

    return history_record;
}

void FileContainerZip::read_history(std::list<HistoryRecord> &list, FILE *f, file_size_t size)
{
    if (size < (long int)sizeof(EndOfCentralDirectory)) {
        return;
    }

    // search "end of central directory" record

    char buffer[(1 << 16) + sizeof(EndOfCentralDirectory)];
    String comment;
    size_t read_size = size > (long int)sizeof(buffer)
                       ? sizeof(buffer) : (size_t)size;
    fseek(f, (long int)size - (long int)read_size, SEEK_SET);
    read_size = fread(&buffer, 1, read_size, f);
    bool found = false;
    HistoryRecord history_record;

    for (int i = read_size - sizeof(EndOfCentralDirectory); i >= 0; i--) {
        EndOfCentralDirectory *e = (EndOfCentralDirectory*)&buffer[i];

        if (e->signature == EndOfCentralDirectory::valid_signature__
                && e->comment_length == (uint16_t)(read_size - sizeof(EndOfCentralDirectory) - i)) {
            // found
            if (e->comment_length > 0) {
                comment = String(buffer + i + sizeof(EndOfCentralDirectory), e->comment_length);
                history_record = decode_history(comment);
                history_record.storage_size = size;
                found = true;
            }

            break;
        }
    }

    if (found) {
        list.front() = history_record;

        if (history_record.prev_storage_size > 0 && history_record.prev_storage_size < size) {
            list.push_front(HistoryRecord(0, history_record.prev_storage_size));
            read_history(list, f, history_record.prev_storage_size);
        }
    }
}

std::list<FileContainerZip::HistoryRecord> FileContainerZip::read_history(const String &container_filename)
{
    std::list<HistoryRecord> list;

    FILE *f = fopen(container_filename.c_str(), "rb");

    if (f == NULL) {
        return list;
    }

    fseek(f, 0, SEEK_END);
    long int size = ftell(f);

    if (size >= (long int)sizeof(EndOfCentralDirectory)) {
        list.push_front(HistoryRecord(0, size));
        read_history(list, f, size);
    }

    fclose(f);
    return list;
}

bool FileContainerZip::create(const String &container_filename)
{
    if (is_opened()) {
        return false;
    }

    storage_file_ = fopen(fix_slashes(container_filename).c_str(), "w+b");

    if (is_opened()) {
        changed_ = true;
    }

    return is_opened();
}

bool FileContainerZip::open_from_history(const String &container_filename, file_size_t truncate_storage_size)
{
    if (is_opened()) {
        return false;
    }

    FILE *f = fopen(fix_slashes(container_filename).c_str(), "r+b");

    if (f == NULL) {
        return false;
    }

    // check size of file
    fseek(f, 0, SEEK_END);
    long int filesize = ftell(f);
    long int actual_filesize = filesize;

    if (filesize < (long int)sizeof(EndOfCentralDirectory)) {
        fclose(f);
        return false;
    }

    if (truncate_storage_size > 0 && truncate_storage_size < filesize) {
        filesize = (long int)truncate_storage_size;
    }

    char buffer[(1 << 16) + sizeof(EndOfCentralDirectory)];

    // search "end of central directory" record
    EndOfCentralDirectory ecd;
    size_t read_size = filesize > (long int)sizeof(buffer)
                       ? sizeof(buffer) : (size_t)filesize;
    fseek(f, filesize - (long int)read_size, SEEK_SET);
    read_size = fread(&buffer, 1, read_size, f);
    bool found = false;

    for (int i = read_size - sizeof(EndOfCentralDirectory); i >= 0; i--) {
        EndOfCentralDirectory *e = (EndOfCentralDirectory*)&buffer[i];

        if (e->signature == EndOfCentralDirectory::valid_signature__
                && e->comment_length == (uint16_t)(read_size - sizeof(EndOfCentralDirectory) - i)) {
            ecd = *e;
            found = true;
            break;
        }
    }

    if (!found) {
        fclose(f);
        return false;
    }

    // read "central directory"
    FileMap files;
    fseek(f, ecd.offset, SEEK_SET);

    for (int i = 0; i < ecd.current_records; i++) {
        CentralDirectoryFileHeader cdfh;

        if (sizeof(cdfh) != fread(&cdfh, 1, sizeof(cdfh), f)) {
            fclose(f);
            return false;
        }

        // read name, comment and extrafield
        size_t extra_size = cdfh.filename_length
                            + cdfh.filecomment_length
                            + cdfh.extrafield_length;

        if (extra_size != fread(buffer, 1, extra_size, f)) {
            fclose(f);
            return false;
        }

        if (cdfh.filename_length > 0
                && (cdfh.flags & 0x0071) == 0) {
            FileInfo info;

            if (buffer[cdfh.filename_length - 1] == '/') {
                info.name = String(buffer, buffer + cdfh.filename_length - 1);
                info.is_directory = true;
            } else {
                info.name = String(buffer, buffer + cdfh.filename_length);
            }

            info.directory_saved = info.is_directory;
            info.size = cdfh.compressed_size;
            info.header_offset = cdfh.offset;
            info.compression = cdfh.compression;
            info.crc32 = cdfh.crc32;
            info.time = DOSTimestamp(cdfh.modification_time, cdfh.modification_date).get_time();
            info.split_name();
            files[info.name] = info;
        }
    }

    // create directories
    for (FileMap::iterator i = files.begin(); i != files.end();) {
        if (!i->second.name_part_directory.empty()
                && files.find(i->second.name_part_directory) == files.end()) {
            FileInfo info;
            info.name = i->second.name_part_directory;
            info.is_directory = true;
            info.time = time(NULL);
            info.split_name();
            files[ info.name ] = info;
            i = files.begin();
        } else {
            i++;
        }
    }

    // loaded
    fseek(f, 0, SEEK_END);
    storage_file_ = f;
    files_.swap(files);
    prev_storage_size_ = actual_filesize;
    file_reading_ = false;
    file_writing_ = false;
    changed_ = false;
    return true;
}

bool FileContainerZip::open(const String &container_filename)
{
    return open_from_history(container_filename);
}

bool FileContainerZip::save()
{
    if (file_is_opened()) {
        return false;
    }

    if (!changed_) {
        return true;
    }

    fseek(storage_file_, 0, SEEK_END);

    // write headers of new directories
    for (FileMap::iterator i = files_.begin(); i != files_.end(); i++) {
        FileInfo &info = i->second;

        if (info.is_directory && !info.directory_saved) {
            LocalFileHeader lfh;
            lfh.version = 20;
            lfh.filename_length = info.name.size() + 1;
            DOSTimestamp dos_timestamp(info.time);
            lfh.modification_time = dos_timestamp.dos_time;
            lfh.modification_date = dos_timestamp.dos_date;

            info.header_offset = ftell(storage_file_);

            if (sizeof(lfh) != fwrite(&lfh, 1, sizeof(lfh), storage_file_)) {
                return false;
            }

            if (info.name.size() != fwrite(info.name.c_str(), 1, info.name.size(), storage_file_)) {
                return false;
            }

            if ((int)'/' != fputc('/', storage_file_)) {
                return false;
            }

            info.directory_saved = true;
        }
    }

    // write central directory
    uint32_t central_directory_offset = (uint32_t)ftell(storage_file_);

    for (FileMap::iterator i = files_.begin(); i != files_.end(); i++) {
        FileInfo &info = i->second;
        CentralDirectoryFileHeader cdfh;
        cdfh.min_version = 20;
        cdfh.offset = info.header_offset;
        cdfh.compressed_size = cdfh.uncompressed_size = info.size;
        cdfh.crc32 = info.crc32;
        cdfh.filename_length = (uint16_t)info.name.size();

        if (info.is_directory) {
            cdfh.filename_length++;
        }

        DOSTimestamp dos_timestamp(info.time);
        cdfh.modification_time = dos_timestamp.dos_time;
        cdfh.modification_date = dos_timestamp.dos_date;

        // write header
        if (sizeof(cdfh) != fwrite(&cdfh, 1, sizeof(cdfh), storage_file_)) {
            return false;
        }

        // write name
        if (info.name.size() != fwrite(info.name.c_str(), 1, info.name.size(), storage_file_)) {
            return false;
        }

        if (info.is_directory)
            if ((int)'/' != fputc('/', storage_file_)) {
                return false;
            }
    }

    // end of central directory
    EndOfCentralDirectory ecd;
    ecd.offset = central_directory_offset;
    ecd.current_records = ecd.total_records = files_.size();
    ecd.size = ftell(storage_file_) - central_directory_offset;
    String comment = encode_history(HistoryRecord(prev_storage_size_));
    ecd.comment_length = comment.size();

    // write header
    if (sizeof(ecd) != fwrite(&ecd, 1, sizeof(ecd), storage_file_)) {
        return false;
    }

    // write comment
    if (ecd.comment_length > 0
            && ecd.comment_length != fwrite(comment.c_str(), 1, ecd.comment_length, storage_file_)) {
        return false;
    }

    prev_storage_size_ = ftell(storage_file_);
    fflush(storage_file_);
    changed_ = false;
    return true;
}

void FileContainerZip::close()
{
    if (!is_opened()) {
        return;
    }

    // close opened file if need
    file_close();

    save();

    // close storage file and clead variables
    fclose(storage_file_);
    storage_file_ = NULL;
    files_.clear();
    prev_storage_size_ = 0;
    file_reading_ = false;
    file_writing_ = false;
    changed_ = false;
}

bool FileContainerZip::is_opened()
{
    return storage_file_ != NULL;
}

bool FileContainerZip::is_file(const String &filename)
{
    if (!is_opened()) {
        return false;
    }

    FileMap::const_iterator i = files_.find(fix_slashes(filename));
    return i != files_.end() && !i->second.is_directory;
}

bool FileContainerZip::is_directory(const String &filename)
{
    if (!is_opened()) {
        return false;
    }

    if (filename.empty()) {
        return true;
    }

    FileMap::const_iterator i = files_.find(fix_slashes(filename));
    return i != files_.end() && i->second.is_directory;
}

bool FileContainerZip::directory_check_name(const String &dirname)
{
    return dirname.size() <= (1 << 16) - 2 - sizeof(CentralDirectoryFileHeader);
}

bool FileContainerZip::directory_create(const String &dirname)
{
    if (!is_opened()) {
        return false;
    }

    if (is_file(dirname)) {
        return false;
    }

    if (is_directory(dirname)) {
        return true;
    }

    if (!directory_check_name(dirname)) {
        return false;
    }

    FileInfo info;
    info.name = fix_slashes(dirname);
    info.split_name();
    info.is_directory = true;
    info.time = time(NULL);

    if (info.name_part_localname.empty()
            || !is_directory(info.name_part_directory)) {
        return false;
    }

    changed_ = true;
    files_[info.name] = info;
    return true;
}

bool FileContainerZip::directory_scan(const String &dirname, FileList &out_files)
{
    out_files.clear();

    if (!is_directory(dirname)) {
        return false;
    }

    for (FileMap::iterator i = files_.begin(); i != files_.end(); i++)
        if (i->second.name_part_directory == fix_slashes(dirname)) {
            out_files.push_back(i->second.name_part_localname);
        }

    return true;
}

bool FileContainerZip::file_remove(const String &filename)
{
    if (is_directory(filename)) {
        FileList files;
        directory_scan(filename, files);

        if (!files.empty()) {
            return false;
        }

        changed_ = true;
        files_.erase(fix_slashes(filename));
    } else if (is_file(filename)) {
        if (file_is_opened() && file_->first == fix_slashes(filename)) {
            return false;
        }

        changed_ = true;
        files_.erase(fix_slashes(filename));
    }

    return true;
}

bool FileContainerZip::file_check_name(const String &filename)
{
    return filename.size() <= (1 << 16) - 1 - sizeof(CentralDirectoryFileHeader);
}

bool FileContainerZip::file_open_read_whole_container()
{
    if (!is_opened() || file_is_opened()) {
        return false;
    }

    fseek(storage_file_, 0, SEEK_SET);
    file_reading_whole_container_ = true;
    file_processed_size_ = 0;
    return true;
}

bool FileContainerZip::file_open_read(const String &filename)
{
    if (!is_opened() || file_is_opened()) {
        return false;
    }

    file_ = files_.find(fix_slashes(filename));

    if (file_ == files_.end() || file_->second.is_directory) {
        return false;
    }

    // read header
    LocalFileHeader lfh;
    fseek(storage_file_, file_->second.header_offset, SEEK_SET);

    if (sizeof(lfh) != fread(&lfh, 1, sizeof(lfh), storage_file_)) {
        return false;
    }

    if (lfh.signature != LocalFileHeader::valid_signature__) {
        return false;
    }

    // seek to file begin
    fseek(storage_file_, lfh.filename_length + lfh.extrafield_length, SEEK_CUR);
    file_reading_ = true;
    file_processed_size_ = 0;
    return true;
}

bool FileContainerZip::file_open_write(const String &filename)
{
    if (!is_opened() || file_is_opened()) {
        return false;
    }

    if (!file_check_name(filename)) {
        return false;
    }

    file_ = files_.find(fix_slashes(filename));

    FileInfo new_info;

    if (file_ == files_.end()) {
        // create new file
        new_info.name = fix_slashes(filename);
        new_info.split_name();

        if (new_info.name_part_localname.empty()
                || !is_directory(new_info.name_part_directory)) {
            return false;
        }
    } else if (file_->second.is_directory) {
        return false;
    }

    FileInfo &info = file_ == files_.end() ? new_info : file_->second;

    // write header
    LocalFileHeader lfh;
    time_t t = time(NULL);
    lfh.version = 20;
    lfh.filename_length = info.name.size();
    DOSTimestamp dos_timestamp(t);
    lfh.modification_time = dos_timestamp.dos_time;
    lfh.modification_date = dos_timestamp.dos_date;

    fseek(storage_file_, 0, SEEK_END);
    long int offset = ftell(storage_file_);
    changed_ = true;

    if (sizeof(lfh) != fwrite(&lfh, 1, sizeof(lfh), storage_file_)) {
        return false;
    }

    if (info.name.size() != fwrite(info.name.c_str(), 1, info.name.size(), storage_file_)) {
        return false;
    }

    // update file info
    info.header_offset = offset;
    info.size = 0;
    info.compression = 0;
    info.crc32 = 0;
    info.time = t;

    if (file_ == files_.end()) {
        files_[new_info.name] = new_info;
        file_ = files_.find(fix_slashes(filename));
    }

    file_writing_ = true;
    file_processed_size_ = 0;
    return true;
}

void FileContainerZip::file_close()
{
    if (file_is_opened_for_write()) {
        LocalFileHeaderOverwrite lfho;
        lfho.crc32 = file_->second.crc32;
        lfho.compressed_size = lfho.uncompressed_size = file_->second.size;
        fseek(storage_file_, file_->second.header_offset + LocalFileHeaderOverwrite::offset_from_header(), SEEK_SET);
        fwrite(&lfho, 1, sizeof(lfho), storage_file_);
        file_writing_ = false;
        fflush(storage_file_);
    }

    file_reading_whole_container_ = false;
    file_reading_ = false;
    file_writing_ = false;
    file_processed_size_ = 0;

    // call base-class method to invalidate streams
    FileContainer::file_close();
}

bool FileContainerZip::file_is_opened_for_read()
{
    return is_opened() && (file_reading_ || file_reading_whole_container_);
}

bool FileContainerZip::file_is_opened_for_write()
{
    return is_opened() && file_writing_;
}

size_t FileContainerZip::file_read(void *buffer, size_t size)
{
    if (!file_is_opened_for_read()) {
        return 0;
    }

    file_size_t file_size = file_reading_whole_container_
                            ? prev_storage_size_ : file_->second.size;
    file_size_t remain_size = file_size - file_processed_size_;
    size_t s = remain_size > (file_size_t)size ? size : (size_t)remain_size;
    s = fread(buffer, 1, s, storage_file_);
    file_processed_size_ += s;
    return s;
}

size_t FileContainerZip::file_write(const void *buffer, size_t size)
{
    if (!file_is_opened_for_write()) {
        return 0;
    }

    size_t s = fwrite(buffer, 1, size, storage_file_);
    file_processed_size_ += s;
    file_->second.size = file_processed_size_;
    file_->second.crc32 = crc32(file_->second.crc32, buffer, s);
    return s;
}

FileSystem::ReadStream::Handle FileContainerZip::get_read_stream(const String &filename)
{
    FileSystem::ReadStream::Handle stream = FileContainer::get_read_stream(filename);

    if (stream
            && file_is_opened_for_read()
            && !file_reading_whole_container_
            && file_->second.compression > 0) {
        return new ZReadStream(stream);
    }

    return stream;
}